This invention relates generally to a charged particle beam apparatus which can operate ions or electrons, and more particularly to a charged particle beam apparatus which includes a charged particle optical system suitable to selectively derive certain ions and electrons in the same optical system and in the same vacuum space.
One such previously known apparatus having the functions of mass separation and blanking (modulation) is a maskless ion implantation apparatus equipped with a mass separator, as disclosed in the Japanese Journal "OYO BUTSURI (Applied Physics)" Vol. 53, No. 8 (1984) pp. 704 to 708. In this prior art apparatus, in order for only certain ions to be subjected to the mass separation and blanking, an E.times.B type mass separator (Wien filter) is used; the above functions could be performed by varying only the electric field with the magnetic field fixed. In this prior art, however, consideration was not given to such an optical system as being capable of controlling electrons, which have very small mass, in addition to the ions. Therefore, this prior art is not satisfactory in that it is difficult to perform the functions of mass separation and blanking (modulation) for both the ions and electrons.